Virtual-tributary switch rolls

Fremont, Calif. - A virtual-tributary Sonet/SDH cross-connect switch IC for metro-area networks offers an aggregate bandwidth of 2.488 Gbits/second (OC-48). The PX4800 Viti-48 from Paxonet Communications Inc. is a single-stage, nonblocking switch for virtual tributaries across a full OC-48 data stream that can be subdivided into combinations of STS-12 (594.432 Mbits/s), STS-3 (155.52 Mbits/s) and STS-1 (51.84 Mbits/s). The chip is intended for use in multiservice switches and digital-access cross-connect switches as well as in metro optical access networks.

"Viti is aimed at the new generation of multiservice switches that support OC-48 to granular T1, E1, T3 and E3 data streams for grooming and aggregation at the edge of metro optical networks," said Paxonet founder and chief executive officer Chetan Sanghvi. The chip can switch any column in the Sonet/SDH input data stream along with VT1.5, VT2.0 and other standard payload increments. It provides nonblocking switching among 16 STS-3 or four STS-12 input streams, to obtain 16 STS-3 or four STS-12 output streams.

Sanghvi said it can also be cascaded to support an OC-192 stream with any channelization down to 0.5-Mbit/s granularity. "Our device allows developers to integrate digital-access cross-connect switch functions with those of add/drop multiplexers to offer better value to service providers," he said, adding that standard virtual-tributary cross-connect products currently available lack the integration to implement 2.48-Gbit/s or higher levels of aggregate bandwidth.

"There's an increasing need to integrate the current TDM-based infrastructure with newer, packet-based transport platforms," Sanghvi said. "The next-generation metro-service platforms for which our device was designed have the potential to change the economics of service providers' business models by enabling the grooming and aggregation functions at the network's edge."

The chip is packaged in a 352-pin SBGA. It's sampling now and is set for production in March. Priced at $450 in lots of 1,000, it comes with support tools including reference designs, evaluation boards, software drivers and functional bus models.